A 12-year-old boy is examined at the doctor's office. His height is reported as 154 cm. His height in inches is. Round to two decimal places (hundredths place).

A. This is ineffective. Waiting until nausea occurs reduces the effectiveness of antiemetics because CINV is often more difficult to control once established. Nonpharmacologic methods (e.g., relaxation, acupressure) can help, but they are usually adjuncts, not first-line preventive therapy.

B. PRN administration is reactive rather than proactive. Chemotherapy often induces anticipatory or acute nausea, which may not respond fully to medication given after symptoms begin. This approach increases discomfort and the risk of dehydration and electrolyte imbalance.

C. Prophylactic administration ensures that the medication is at therapeutic levels in the bloodstream before chemotherapy begins, preventing or reducing the severity of nausea and vomiting. This approach is supported by clinical guidelines and improves patient comfort and treatment adherence.

D. Delaying scheduled dosing until nausea starts is less effective. Nausea prevention is more effective than treatment after it occurs. Scheduled dosing should begin before or at the start of chemotherapy, not after symptoms develop.

A. Hyposecretion of somatotropin (growth hormone) results in growth retardation or short stature over time, but does not cause acute changes in urine output, sodium balance, or water retention. It is unrelated to the acute presentation described.
B. Hypersecretion of somatotropin leads to gigantism in children or acromegaly in adults. This condition affects growth and skeletal development, not fluid balance or electrolyte disturbances, so it does not explain the current findings.
C. Diabetes Insipidus (DI) involves hyposecretion or resistance to antidiuretic hormone (ADH), leading to polyuria, polydipsia, hypernatremia, and dehydration. The child’s decreased urine output and water retention are opposite of DI manifestations, so DI is inconsistent with this presentation.
D. Syndrome of inappropriate antidiuretic hormone (SIADH) involves excessive release of ADH, leading to water retention, decreased urine output (oliguria), dilutional hyponatremia, and signs of water intoxication. In the context of bacterial meningitis, SIADH is a recognized complication due to stress on the hypothalamic-pituitary axis or CNS irritation. The child’s nausea, headache, and hyponatremia fit the clinical pattern of SIADH, making it the most likely pituitary-related disorder in this scenario.